Update questions.txt file with new questions including tougher analytical ones

- Replace old questions.txt content that was overriding hardcoded questions
- Add the 4 tougher analytical questions:
* Which station records highest variability in PM2.5?
* Calculate pollution improvement rate year-over-year by city
* Identify cities with PM2.5 levels consistently above 50 μg/m³ for >6 months
* Find correlation between PM2.5 and PM10 across different seasons and cities
- Remove old questions like 'Which state has the highest average PM2.5?'
- Now questions should be visible in sidebar since questions.txt takes precedence

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

questions.txt

@@ -1,17 +1,18 @@
-Plot the monthly average PM2.5 for the year 2023.
-Which month has the highest average PM2.5 in 2023 for Mumbai?
-Plot and compare monthly timeseries of pollution for Mumbai and Bengaluru.
-Plot the yearly average PM2.5.
-Plot the monthly average PM2.5 of Delhi, Mumbai and Bengaluru for the year 2022.
-Which month has the highest pollution?
-Which city has the highest PM2.5 level in July 2022?
-Plot and compare the monthly average PM2.5 of Delhi, Mumbai and Bengaluru for the year 2022.
-Plot the monthly average PM2.5.
-Plot the monthly average PM10 for the year 2023.
-Which (month, year) has the highest PM2.5?
-Plot the monthly average PM2.5 of Delhi for the year 2022.
-Plot the monthly average PM2.5 of Bengaluru for the year 2022.
-Plot the monthly average PM2.5 of Mumbai for the year 2022.
-Which state has the highest average PM2.5?
-Plot monthly PM2.5 in Gujarat for 2023.
-What is the name of the month with the highest average PM2.5 overall?
+Which month had highest pollution?
+Which city has worst air quality?
+Show annual PM2.5 average
+Plot monthly average PM2.5 for 2023
+List all cities by pollution level
+Compare winter vs summer pollution
+Show seasonal pollution patterns
+Which areas exceed WHO guidelines?
+What are peak pollution hours?
+Show PM10 vs PM2.5 comparison
+Which station records highest variability in PM2.5?
+Calculate pollution improvement rate year-over-year by city
+Identify cities with PM2.5 levels consistently above 50 μg/m³ for >6 months
+Find correlation between PM2.5 and PM10 across different seasons and cities
+Compare weekday vs weekend levels
+Plot yearly trend analysis
+Show pollution distribution by city
+Create correlation plot between pollutants